Antibacterial Activity And Mechanism Of The Alkaloids In Sophora Flavescens Ait. And Application In Superabsorbent Polymer

Alkaloids in Sophora flavescens Ait. are the total alkaloids extractive thatobtained from the traditional Chinese medicine, like sophora flavescens Ait.,sophora alopecuroides, sophoea subprostrata and so on. It has goodantimicrobial activity on a variety of microorganisms, and it is an ideal plantsource antimicrobial agents. Superabsorbent polymer is a function materialwhich can absorb large amounts of water and has been widely used. In orderto extend the application of alkaloids in Sophora flavescens Ait., this paperintends to use natural plant active components, alkaloids in Sophoraflavescens Ait., as antimicrobial agents to prepare superabsorbent polymer.The main work of this paper is summarized as follows:First, study the antimicrobial effect of alkaloids against four bacterial(E.coli, S.aureus, B.subtilis and B.cereus) and two fungal microorganism(C.albicans, A.oryzae). From the result we found that the alkaloids have verygood antimicrobial activities for the six strains, and especially for E.coli andS.aureus. Then on these basis, the minimum inhibitory concentration andgrowth curve of alkaloids against these two strains was determined. And themechanism of alkaloids on these two strains was investigated by analyzing byanalyzing the morphology, protein and DNA, and intra-and extracellular Na+,K+concentrations. Finally, the mechanism of alkaloids on E.coli and S.aureuswas confirmed as: destroy the cell wall, affect DNA synthesis and geneexpression, resulting in the decrease or elimination of protein synthesis, suchas Na+-K+-pump and finally inhibiting or even killing cells.Then, the best starch graft acrylic acid superabsorbent polymer preparationconditions were explored. And on these basis, superabsorbent polymer withantibacterial activity that based on alkaloids was prepared by surfacemodification method and synthesis method. The superabsorbent polymerwhich was prepared by these two method were compared by detected the water absorbency and antibacterial activity. Comparison found that usingsurface modification method was more practical and feasible. Waterabsorbency of the superabsorbent polymer which was prepared by surfacemodification method was700g/g, and the inhibitory rate for E.coli andS.aureus were about70~100%.Finally, antibacterial activity of the superabsorbent polymer that preparedby surface modification method under nature environment and some otherproperties were measured. The result showed that use2.58%alkaloids tomodified the superabsorbent polymer could make it have a generally wellantibacterial property. The antibacterial superabsorbent polymer also had afast water absorption rate and salt water absorption rate,15min could takeabout715g/g water and reach the swelling equilibrium, and20min could takeabout57g/g salt water and reach the swelling equilibrium. The grafted ratewas90%, the retention rate of the antibacterial superabsorbent polymer under60℃for8h was only7%, indicated that the retention property need toimprove. Though, the retention property was not very well, the antimicrobialsuperabsorbent polymer had a good thermal stability, could withstand hightemperature of250℃。...